Scaffold & emulator

KMock provides two classes specialized in the Kubernetes API mocking:

kmock.KubernetesScaffold provides the basic API endpoints for the cluster information, resource discovery, and Kubernetes-structured errors, but lacks the persistent storage of the objects. The resource meta-information can be added via kmock.resources associative array.

kmock.KubernetesEmulator provides the same as the scaffold class, plus the persistent storages of the objects that can be added, manipulated, and asserted via the kmock.objects associative array, so as via the API endpoints for the creation, patching, deleting, listing and watching of the resources.

By default, the pytest kmock fixture uses the most functionally advanced class — the Kubernetes emulator, unless configured otherwise.

Note that the emulator is not a precise replica of the Kubernetes behaviour — it does not do all the sophisticated logic of special-purpose fields, does not merge lists of items, does not do any background processing. It is essentially a database-over-http with the Kubernetes API URLs — it only stores and retrieves the objects “as is”.

The only place where it interprets the data is taking the name and namespace of the newly created objects — to form their identifying address in the associative array. After that, the identifying address is inferred from the URLs of the patching & deleting endpoints, not from the data.